The present invention relates generally to an optical element switching apparatus for switching the position of a plurality of optical elements, and, for example, to an optical element switching apparatus for selectively positioning one of a plurality of objective lenses on an observation optical axis in an optical microscope.
For example, when a sample such as a living cell is observed, the cell is often fixed in a culture liquid in a dish. In such observation, in normal cases, a large area of the sample is first observed at a low magnification (6xc3x97 magnifications or less) and then a smaller specific area of the sample is observed at a high magnification (10xc3x97 magnifications or more). A high-power objective lens is normally an immersion objective lens which is immersed in a culture liquid. When the objective lens is focused at the surface of the sample, a tip end of the objective lens is located on a level lower than the height of the dish, that is, located inside the dish.
In this type of microscope, when the objective lens is exchanged, it is important to prevent interference between the objective lens and the dish.
To solve this problem, Jpn. U. M. Appln. KOKAI Publication No. 6-4720, for example, discloses an optical microscope having an optical element switching apparatus for retreating the objective lens away from the sample along the observation optical axis so as to prevent interference between the dish and the objective lens at the time of changing the objective lens.
If the objective lens is thus retreated at the time of exchanging the objective lens, interference between the objective lens and the dish can be prevented.
In the optical element switching apparatus of Jpn. U. M. Appln. KOKAI Publication No. 6-4720, however, the objective lens retreat operation (the optical element retreat operation) and the objective lens exchange operation (optical element switching operation) are performed independently. Thus, if the exchange operation is performed erroneously without the retreat operation, the objective lens (optical element) may interfere with the object such as the dish or sample, and the sample or objective lens may be damaged.
The present invention has been made in consideration of the above problem, and its object is to provide an optical element switching apparatus capable of selectively switching optical element without interference between the optical element and the object.
In order to achieve the object, the present invention provides an optical element switching apparatus comprising:
a movement member to which a plurality of optical elements are detachably attached and which is supported to be parallel-linearly movable by means of a guide mechanism;
a drive mechanism for parallel-linearly moving the movement member; and
a guide member for guiding, where said plurality of optical elements are to be switched, the optical element to be switched in such a direction as to retreat from an object when the movement member is to be parallel-linearly moved.
There is also provided an optical microscope incorporating an optical element switching apparatus, the apparatus comprising:
a movement member to which a plurality of objective lenses are detachably attached and which is supported to be parallel-linearly movable by means of a guide mechanism;
a drive mechanism for parallel-linearly moving the movement member; and
a guide member for guiding, where said plurality of objective lenses are to be switched, the objective lens to be switched in such a direction as to retreat from an object when the movement member is to be parallel-linearly moved.
Additional objects and advantages of the invention will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. The objects and advantages of the invention may be realized and obtained by means of the instrumentalities and combinations particularly pointed out hereinafter.